Effects of Sublabeled Rates of Dazomet and Metam-Sodium Applied Under Low-Permeability Films on Calonectria Microsclerotia Survival.

Infested soil is the primary inoculum source for Calonectria spp. for initiating disease in ornamental and forestry crops. The effects of dazomet and metam-sodium on survival of microsclerotia of 28 isolates belonging to 19 Calonectria spp. were evaluated in this study under nursery conditions. Two experiments with exotic Calonectria spp. in plastic containers in a greenhouse and three trials with endemic species in field plots were performed during different seasons. The containers and plots were artificially infested with Calonectria microsclerotia differentiated on carnation leaf tissues. Basamid (dazomet) was applied at 100, 160, 200, 400, and 500 kg/ha, while Divapan (metam-sodium) was applied at 250, 350, 400, 700, and 1,000 liters/ha in both the containers and plots. The fumigants were applied under virtually and totally impermeable films. Fungal survival was evaluated after 21 days using leaf tissues collected from treated soil and plated on potato dextrose agar, and the ability of microsclerotia to cause infection was tested on red clover. The survival of Calonectria inocula and microsclerotia decreased with increasing fumigant rates. In the greenhouse trials, where Basamid was applied at 200, 400, and 500 kg/ha and Divapan at 400, 700, and 1,000 liters/ha, no viable microsclerotia were recovered for 14 exotic Calonectria spp., whereas viable inocula of Calonectria hongkongensis, C. naviculata, and C. sulawesiensis were retrieved from the fumigated plots. Low rates of Basamid (100 and 160 kg/ha) and Divapan (250 and 350 liters/ha) were less effective at reducing Calonectria viability and, for these treatments, the rate of microsclerotia survival was highly variable among the different isolates and species. Furthermore, totally impermeable film significantly enhanced fumigant performance. Relative to endemic Calonectria spp., all of the treatments killed microsclerotia of C. polizzii and C. pauciramosa independent from fumigant, rate, and film. This research demonstrated the possibility of reducing the application rates by up to 160 kg/ha for Basamid and 400 liters/ha for Divapan under low-permeability films (virtually impermeable film or totally impermeable film) for eradicating or reducing the primary inoculum of Calonectria spp. in soil.

Draft Genome Sequence of Calonectria pteridis, the Causal Agent of Calonectria Leaf Blight on Eucalyptus.

Here, we report the draft genome sequence of Calonectria pteridis, the causal agent of Calonectria leaf blight in eucalyptus plantations in Brazil. The 58,373,473-bp genome assembly consists of 1,167 scaffolds, with a GC content of 50.21%. These genomic data can contribute to future studies involving the biology, adaptability, and pathogenicity of C. pteridis.

Optimization of endoglucanase and xylanase activities from Fusarium verticillioides for simultaneous saccharification and fermentation of sugarcane bagasse.

Enzymatic hydrolysis is an important but expensive step in the production of ethanol from biomass. Thus, the production of efficient enzymatic cocktails is of great interest for this biotechnological application. The production of endoglucanase and xylanase activites from F. verticillioides were optimized in a factorial design (2(5)) followed by a CCDR design. Endoglucanase and xylanase activities increased from 2.8 to 8.0 U/mL and from 13.4 to 114 U/mL, respectively. The optimal pH and temperature were determined for endoglucanase (5.6, 80 °C), cellobiase (5.6, 60 °C), FPase (6.0, 55 °C) and xylanase (7.0, 50 °C). The optimized crude extract was applied in saccharification and fermentation of sugarcane bagasse from which 9.7 g/L of ethanol was produced at an ethanol/biomass yield of 0.19.

What is Scirrhia?

The ascomycetous genus Scirrhia is presently treated as a member of Dothideomycetidae, though uncertainty remains as to which family it belongs in Capnodiales, Ascomycota. Recent collections on stems of a fern, Pteridium aquilinum (Dennstaedtiaceae) in Brazil, led to the discovery of a new species of Scirrhia, described here as S.brasiliensis. Based on DNA sequence data of the nuclear ribosomal DNA (LSU), Scirrhia is revealed to represent a member of Dothideomycetes, Capnodiales, Mycosphaerellaceae. Scirrhia is the first confirmed genus in Mycosphaerellaceae to have well developed pseudoparaphyses and a prominent hypostroma in which ascomata are arranged in parallel rows. Given the extremely slow growth rate and difficulty in obtaining cultures of S. brasiliensis on various growth media, it appears that Scirrhia represents a genus of potentially obligate plant pathogens within Mycosphaerellaceae.

What is Johansonia?

The bitunicate ascomycete genus Johansonia is presently treated as a member of Saccardiaceae, a family regarded as incertae sedis within the Ascomycota. Recent collections on leaves of a leguminous host, Dimorphandramollis, in Mato Grosso, Brazil, led to the discovery of a new species of Johansonia, described here as J.chapadiensis. Based on DNA sequence data of the nuclear ribosomal DNA (LSU), Johansonia is revealed to represent a member of Dothideomycetes, Capnodiales. Although its family could not be resolved, it clustered basal to Schizothyriaceae and Mycosphaerellaceae, and could well represent a species of Saccardiaceae. DNA sequence data of other members of Saccardiaceae would be required, however, to confirm this classification.